1. Technical Field
The present invention relates to a liquid detection unit suitable for detecting residue of liquid in a liquid container and a liquid container equipped with the liquid detection unit.
2. Background Art
A technique of detecting the remaining amount of ink (liquid) in an ink cartridge (liquid container) using piezoelectric-type detection means is known (Patent document 1). According to this technique, ink end or ink near-end is detected in a manner such that a sensor constituting the piezoelectric-type detection means is provided with a sensor cavity and electrical characteristic of the piezoelectric-type detection means changes according to presence of ink in the sensor cavity.    Patent Document 1: JP-A-2006-160371
Unlike the technique of Patent document 1, when trying to detect ink end or ink near-end in the state in which the sensor cavity is always filled with ink, it is important to assure that the sensor cavity is completely filled with ink. That is, when the sensor cavity is not completely filled with ink, the result of false detection comes out.